A tocopheryl glycoside as a water-soluble Vitamin E has been reported in U.S. Pat. No. 4,457,918, but which describes neither the concrete compounds including the oligosaccharides having three or more sugar residues, nor the antiviral actions thereof.
Japanese Patent Application First Publication Nos. 60-56994 and 61-30594 describe one- or two-sugar linked tocopheryl glycoside derivatives. However, in these documents, there is no description of the compounds including the oligosaccharides having three or more sugar residues and the tocopheryl glycosides in which lactoses are linked to galactoses, nor are the possibilities for using the same as starting materials of the compounds exhibiting the antiviral actions disclosed.
With regard to sugar sulfates, heretofore, monosaccharide sulfates and polysaccharide sulfates have been known and there are numerous reports related to the sulfates, e.g., Advances in Carbohydrate Chemistry, 20, 183, and Advances in Carbohydrate Chemistry, 25, 407.
Recently, a number of reports have been published wherein the polysaccharide sulfates are useful as the medical agents for Acquired Immune Deficiency Syndrome (AIDS). The reports include, for example, Japanese Patent Application First Publication No. 62-215529, Hideki Nakashima, et al., Jpn. J. Cancer Res. (Gann) 78, 1164 (1987); Osamu Yoshida, et al., Biochemical Pharmacology, 37, 2887.about.2891 (1988); Japanese Patent Application First Publication No. 1-103601; among others.
However, these polysaccharide sulfates have several disadvantages: they have antigenic properties and a strong tendency to act as anticoagulants, and are difficult to administer due to their poor absorption In vivo because of the molecular weights thereof being in excess of 10,000.
In addition, since 3'-azido-3'-deoxythymidine (AZT) (which is a nucleic acid derivative, and which has come to be broadly employed as an anti-AIDS agent) exhibits strong side effects, development of a novel chemical agent having low toxicity is desired.